My answering machine picked up.
Fast talking woman robo-call.
"You've won a free cruise for two to the Bahamas -- IF you complete the following survey. Say 'yes' to begin."
I didn't pick up. The voice continued.
"Otherwise, say No to be removed from the calling list of National Statistical Survey Studies.... more silence... Your name will be removed from our calling list."
From everything I've seen these are people trying to steal your identity or pull some sort of scam.
They claim their call is a survey, because surveys are exempt from robo-call laws.
Do NOT say Yes, or do NOT press any buttons on your phone.
One caller did, and complained that afterward they had huge charges on their phone bill.